/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.elasticsearch.common.component;

import org.elasticsearch.ElasticsearchException;

/**
 *  生命周期组件
 *   start, stop, close 是组件运行过程中的几种状态
 */
public interface LifecycleComponent<T> extends CloseableComponent {

    Lifecycle.State lifecycleState();

    /**
     * 添加监听器
     * @param listener
     */
    void addLifecycleListener(LifecycleListener listener);

    /**
     * 移除监听器
     * @param listener
     */
    void removeLifecycleListener(LifecycleListener listener);

    /**
     * 开启模块的服务
     * @return
     * @throws ElasticsearchException
     */
    T start() throws ElasticsearchException;

    /**
     * 停止服务
     * @return
     * @throws ElasticsearchException
     */
    T stop() throws ElasticsearchException;
}
